The Edit UVWs dialog menu bar provides access to a number of important editing commands. Some of these commands are replicated on the dialog toolbar and the Unwrap UVW command panel; others, such as the Mapping, Stitch, and Sketch tools, are available only from the menus.
Restores the UVW coordinates to their original status.
Reset All has almost the same effect as removing and reapplying the modifier, except that a map assigned in the Edit UVWs dialog is not deleted. For example, if you forgot to turn on the Generate Mapping Coordinates check box for an object, and then applied the Unwrap UVW modifier, the modifier would have no UVW coordinates to use and its settings would be wrong. If you then go back in the modifier stack and turn on Generate Mapping Coordinates, you'd need to choose the Reset All command. When you do so, an alert warns you that you're losing any edits you've made.
These commands provide access to the different transform functions, and copy and paste selections.
Applies the texture mapping coordinates in the paste buffer to the current selection. Using Paste repeatedly with the same target coordinates causes the coordinates to rotate by 90 degrees each time.
Use Copy and Paste to apply the same mapping coordinates (i.e., image) to a number of different geometry faces. A typical example of usage would be in designing a game level, where you're working with a multi-image texture map, part of which is a door image. You might want to apply the same door image to several different door polygons. First, you would select one of the door polys and position it over the door image. Next, use Copy to place its texture coordinates in the paste buffer. Then select another door poly and choose Paste or Paste Weld. The door's texture coordinates move to the same location as the original poly. Continue selecting other door polys and pasting until all the doors are mapped.
Applies the contents of the paste buffer to the current selection and then welds coincident vertices, effectively fusing the source and destination selections together.
Use this function to end up with a single set of texture coordinates that's applied to multiple geometry elements. Adjusting these texture coordinates changes the mapping for all geometry to which they're applied.
Lets you select and transform vertices. See Freeform Mode.
These commands let you copy a viewport selection to the editor, and transfer selections among the three different sub-object modes.
Converts the current edge selection to a face selection and places you in Face sub-object mode. For a face to be selected, the current edge selection must include all of its vertices. For example, if two opposite edges of a four-sided face are selected, the edge selection includes all four of the face's vertices, so this command will select the face.
Selects any faces facing away from the current mapping. Available only in Face selection mode.
This is useful in complex models for finding faces on a surface that folds in under itself, thus causing potential problems with bump mapping.
For example, add a sphere, turn off Generate Mapping Coords, and them apply Unwrap UVW. This causes the modifier to apply
planar mapping from the top down, so that all faces on the bottom half of the sphere are “inverted”; that is, they face away
from the mapping. In the modifier stack display, highlight the Select Face sub-object level, and then click the Edit button
to open the UVW editor. Choose the Face selection mode, and then choose Select 
Select Inverted Faces. In the viewports, the bottom half of the sphere turns red to indicate that the inverted faces are
now selected.
Selects any faces that overlap other faces. If no face is selected, this selects all overlapping faces. If a face selection exists, this selects only overlapping faces within the selection. Available only in Face selection mode.
When working with complex meshes, it's common for texture-coordinate faces to overlap one another, with the result that they use the same portion of the texture map. Use this command to find overlapping faces in order to separate them as needed.
Tools on this menu let you flip and mirror texture coordinates, weld vertices, combine and separate sets of texture coordinates, and sketch outlines for multiple selected vertices.
Unwrap Editor Options group, as well as on the Unwrap Options dialog Misc. Preferences group.
Welds pairs of vertices or edges. Not available at the Face sub-object level.
Turn on Target Weld, and then drag one vertex to another vertex, or one edge to another edge. As you drag, the cursor changes in appearance to cross hairs when it's over a valid sub-object. While this command is active, you can continue welding sub-objects, and change the sub-object level. To exit Target Weld mode, right-click in the editor window.
Applies to the current selection; works differently in the three sub-object modes. At the Vertex sub-object level, Break replaces each shared vertex with two vertices. With edges, Break requires at least two contiguous edges to be selected, and separates each edge into two. With faces, Break splits the selection off from the rest of the mesh into a new element, exactly as does Detach Edge Verts.
For the current selection, finds all the texture vertices that are assigned to the same geometric vertex, brings them all to the same spot, and welds them together. With this tool you can automatically connect faces that are contiguous in the object mesh but not in the editor.
To use Stitch Selected, first select sub-objects along an edge you want to connect (by default, this causes the shared edges to highlight), and then choose the command. In the Stitch Tool dialog, adjust the settings, and then click OK to accept or Cancel to abort.
Distributes all texture-coordinate clusters through the texture space using one of two methods and spacing you specify. This is useful if you have several overlapping clusters and wish to separate them.
Choosing Pack UVs opens the Pack dialog.
Rescale ClustersLets you draw outlines for vertex selections with the mouse. This is useful for matching coordinate cluster outlines to sections of the texture map en masse, without having to move vertices one at a time.
Choosing Sketch Vertices opens the Sketch Tool dialog. Sketch Vertices is available only in the Vertex sub-object mode.
Opens the non-modal Relax Tool dialog, which lets you change the apparent surface tension in a selection of texture vertices by moving vertices closer to, or away from, their neighbors. Relaxing texture vertices can make them more evenly spaced, resulting in easier texture mapping. Available at all sub-object levels.
Opens the Render UVs dialog, which lets you export texture mapping data as an image file that you can then import into 2D paint software.
Lets you apply one of three different types of automatic, procedural mapping methods to a model. Each method provides settings so you can adjust the mapping to the geometry you're using.
With each method, the mapping is applied to the current face selection; if there is no face selection it is applied to the entire mesh.
Here's a quick overview of the available methods:
Applies planar maps to groups of contiguous faces that fall within a specified angle threshold.
Choosing Flatten Mapping opens the Flatten Mapping dialog.
Applies planar maps based on different vector-projection methods.
Choosing Normal Mapping opens the Normal Mapping dialog.
Unfolds the mesh so you get no face distortion, but does not guarantee that faces will not overlap.
Choosing Unfold Mapping opens the Unfold Mapping dialog.
Opens the Unwrap Options dialog.
When on, the editor displays UVW vertices of the viewport selection at the Face sub-object level of the modifier, and hides the rest.
This is a quick way to work on a limited selection of the texture coordinates of a complex mesh while ignoring the rest. You can turn this on, go to the Face sub-object level of the Unwrap UVW modifier, and select the portion of the object whose texture coordinates you want to edit; only those coordinates appear in the editor, and remain visible even when you change the sub-object level. To work on a different portion, return to the Face level and change the selection in the viewport; the editor window updates to the new selection automatically.
Uses a green-to-red color range to depict distortion: how far in length texture edges are from their corresponding geometry edges. The greater the disparity in lengths (that is, the greater the distortion), the redder the edge appears in the Edit UVW dialog window. Also draws end segments of edges that are too long as white, showing the difference in length from that of the geometry edge.
Left: Texture edges the same as or very close to geometry edges in length are green.
Center: Texture edges slightly different from geometry edges in length are brown.
Right: Texture edges very different from geometry edges in length are red.
When texture edges are longer than geometry edges, white end segments depict length disparity.
Use this display as a way to view where the areas of greatest distortion are in your texture mesh. If an edge is brown or red but doesn't have white end segments, it's too short. If it's brown or red and has white end segments, it's too long, by the total length of the white segments.
When turned on, for the current selection, highlights any shared vertices and/or edges. You can change the highlight color on the Unwrap Options dialog.
Modify panel